你怎么走程序的啊？好程序就是要简洁。这里是n=1000的输出结果。你运行一下看看吧。

wangqingshui(忘情水)

本文发表在 rolia.net 枫下论坛1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36 40 45 48 50 54 60 64 72 75 80 81 90 96 100 108 120 125 128 135 144 150 160 162 180 192 200 216 225 240 243 250 256 270 288 300 320 324 360 375 384 400 405 432 450 480 486 500 512 540 576 600 625 640 648 675 720 729 750 768 800 810 864 900 960 972 1000 1024 1080 1125 1152 1200 1215 1250 1280 1296 1350 1440 1458 1500 1536 1600 1620 1728 1800 1875 1920 1944 2000 2025 2048 2160 2187 2250 2304 2400 2430 2500 2560 2592 2700 2880 2916 3000 3072 3125 3200 3240 3375 3456 3600 3645 3750 3840 3888 4000 4050 4096 4320 4374 4500 4608 4800 4860 5000 5120 5184 5400 5625 5760 5832 6000 6075 6144 6250 6400 6480 6561 6750 6912 7200 7290 7500 7680 7776 8000 8100 8192 8640 8748 9000 9216 9375 9600 9720 10000 10125 10240 10368 10800 10935 11250 11520 11664 12000 12150 12288 12500 12800 12960 13122 13500 13824 14400 14580 15000 15360 15552 15625 16000 16200 16384 16875 17280 17496 18000 18225 18432 18750 19200 19440 19683 20000 20250 20480 20736 21600 21870 22500 23040 23328 24000 24300 24576 25000 25600 25920 26244 27000 27648 28125 28800 29160 30000 30375 30720 31104 31250 32000 32400 32768 32805 33750 34560 34992 36000 36450 36864 37500 38400 38880 39366 40000 40500 40960 41472 43200 43740 45000 46080 46656 46875 48000 48600 49152 50000 50625 51200 51840 52488 54000 54675 55296 56250 57600 58320 59049 60000 60750 61440 62208 62500 64000 64800 65536 65610 67500 69120 69984 72000 72900 73728 75000 76800 77760 78125 78732 80000 81000 81920 82944 84375 86400 87480 90000 91125 92160 93312 93750 96000 97200 98304 98415 100000 101250 102400 103680 104976 108000 109350 110592 112500 115200 116640 118098 120000 121500 122880 124416 125000 128000 129600 131072 131220 135000 138240 139968 140625 144000 145800 147456 150000 151875 153600 155520 156250 157464 160000 162000 163840 164025 165888 168750 172800 174960 177147 180000 182250 184320 186624 187500 192000 194400 196608 196830 200000 202500 204800 207360 209952 216000 218700 221184 225000 230400 233280 234375 236196 240000 243000 245760 248832 250000 253125 256000 259200 262144 262440 270000 273375 276480 279936 281250 288000 291600 294912 295245 300000 303750 307200 311040 312500 314928 320000 324000 327680 328050 331776 337500 345600 349920 354294 360000 364500 368640 373248 375000 384000 388800 390625 393216 393660 400000 405000 409600 414720 419904 421875 432000 437400 442368 450000 455625 460800 466560 468750 472392 480000 486000 491520 492075 497664 500000 506250 512000 518400 524288 524880 531441 540000 546750 552960 559872 562500 576000 583200 589824 590490 600000 607500 614400 622080 625000 629856 640000 648000 655360 656100 663552 675000 691200 699840 703125 708588 720000 729000 737280 746496 750000 759375 768000 777600 781250 786432 787320 800000 810000 819200 820125 829440 839808 843750 864000 874800 884736 885735 900000 911250 921600 933120 937500 944784 960000 972000 983040 984150 995328 1000000 1012500 1024000 1036800 1048576 1049760 1062882 1080000 1093500 1105920 1119744 1125000 1152000 1166400 1171875 1179648 1180980 1200000 1215000 1228800 1244160 1250000 1259712 1265625 1280000 1296000 1310720 1312200 1327104 1350000 1366875 1382400 1399680 1406250 1417176 1440000 1458000 1474560 1476225 1492992 1500000 1518750 1536000 1555200 1562500 1572864 1574640 1594323 1600000 1620000 1638400 1640250 1658880 1679616 1687500 1728000 1749600 1769472 1771470 1800000 1822500 1843200 1866240 1875000 1889568 1920000 1944000 1953125 1966080 1968300 1990656 2000000 2025000 2048000 2073600 2097152 2099520 2109375 2125764 2160000 2187000 2211840 2239488 2250000 2278125 2304000 2332800 2343750 2359296 2361960 2400000 2430000 2457600 2460375 2488320 2500000 2519424 2531250 2560000 2592000 2621440 2624400 2654208 2657205 2700000 2733750 2764800 2799360 2812500 2834352 2880000 2916000 2949120 2952450 2985984 3000000 3037500 3072000 3110400 3125000 3145728 3149280 3188646 3200000 3240000 3276800 3280500 3317760 3359232 3375000 3456000 3499200 3515625 3538944 3542940 3600000 3645000 3686400 3732480 3750000 3779136 3796875 3840000 3888000 3906250 3932160 3936600 3981312 4000000 4050000 4096000 4100625 4147200 4194304 4199040 4218750 4251528 4320000 4374000 4423680 4428675 4478976 4500000 4556250 4608000 4665600 4687500 4718592 4723920 4782969 4800000 4860000 4915200 4920750 4976640 5000000 5038848 5062500 5120000 5184000 5242880 5248800 5308416 5314410 5400000 5467500 5529600 5598720 5625000 5668704 5760000 5832000 5859375 5898240 5904900 5971968 6000000 6075000 6144000 6220800 6250000 6291456 6298560 6328125 6377292 6400000 6480000 6553600 6561000 6635520 6718464 6750000 6834375 6912000 6998400 7031250 7077888 7085880 7200000 7290000 7372800 7381125 7464960 7500000 7558272 7593750 7680000 7776000 7812500 7864320 7873200 7962624 7971615 8000000 8100000 8192000 8201250 8294400 8388608 8398080 8437500 8503056 8640000 8748000 8847360 8857350 8957952 9000000 9112500 9216000 9331200 9375000 9437184 9447840 9565938 9600000 9720000 9765625 9830400 9841500 9953280 10000000 10077696 10125000 10240000 10368000 10485760 10497600 10546875 10616832 10628820 10800000 10935000 11059200 11197440 11250000 11337408 11390625 11520000 11664000 11718750 11796480 11809800 11943936 12000000 12150000 12288000 12301875 12441600 12500000 12582912 12597120 12656250 12754584 12800000 12960000 13107200 13122000 13271040 13286025 13436928 13500000 13668750 13824000 13996800 14062500 14155776 14171760 14348907 14400000 14580000 14745600 14762250 14929920 15000000 15116544 15187500 15360000 15552000 15625000 15728640 15746400 15925248 15943230 16000000 16200000 16384000 16402500 16588800 16777216 16796160 16875000 17006112 17280000 17496000 17578125 17694720 17714700 17915904 18000000 18225000 18432000 18662400 18750000 18874368 18895680 18984375 19131876 19200000 19440000 19531250 19660800 19683000 19906560 20000000 20155392 20250000 20480000 20503125 20736000 20971520 20995200 21093750 21233664 21257640 21600000 21870000 22118400 22143375 22394880 22500000 22674816 22781250 23040000 23328000 23437500 23592960 23619600 23887872 23914845 24000000 24300000 24576000 24603750 24883200 25000000 25165824 25194240 25312500 25509168 25600000 25920000 26214400 26244000 26542080 26572050 26873856 27000000 27337500 27648000 27993600 28125000 28311552 28343520 28697814 28800000 29160000 29296875 29491200 29524500 29859840 30000000 30233088 30375000 30720000 31104000 31250000 31457280 31492800 31640625 31850496 31886460 32000000 32400000 32768000 32805000 33177600 33554432 33592320 33750000 34012224 34171875 34560000 34992000 35156250 35389440 35429400 35831808 36000000 36450000 36864000 36905625 37324800 37500000 37748736 37791360 37968750 38263752 38400000 38880000 39062500 39321600 39366000 39813120 39858075 40000000 40310784 40500000 40960000 41006250 41472000 41943040 41990400 42187500 42467328 42515280 43046721 43200000 43740000 44236800 44286750 44789760 45000000 45349632 45562500 46080000 46656000 46875000 47185920 47239200 47775744 47829690 48000000 48600000 48828125 49152000 49207500 49766400 50000000 50331648 50388480 50625000 51018336 51200000更多精彩文章及讨论，请光临枫下论坛 rolia.net

(#5149129@0)
Last Updated: 2009-3-27
This post has been archived. It cannot be replied.

俺看了好几遍没看懂：（ -copperbean(豆泡果之铜豌豆); 2009-3-19 (#5127219@0)

regular number 的定义 -bobo123(以马内利); 2009-3-19 {43} (#5127298@0)
regular number 定义为 ( 2^ i * 3 ^j * 5^k)

哎哟喂，直接被雷倒了。看哪位大侠上来解答，俺也长长知识。 -copperbean(豆泡果之铜豌豆); 2009-3-19 (#5127338@0)

难就难在只能用 O(n) time ... -ealton(ealton); 2009-3-19 (#5127348@0)

can you explain "O(n) time" in easy-bo-be-understand way? -qwertyasd(东北人); 2009-3-19 (#5127501@0)

请看。。。不知道我解释的好不好。。。 -ealton(ealton); 2009-3-19 {1092} (#5127557@0)
本文发表在 rolia.net 枫下论坛n is the # of regular numbers that is needed to put in the array, the running time should be proportional to n, that is it must be in the form of 'an + b', where a and b are constants, however, the running time can't be one of these: n^2, n^3, n*log n, etc... in other words, what you do to each one of the n numbers should be a constant time, result a total running time of O(n)

for example, the following code takes O(n log n) times, because the running time of the while loop isn't constant, it depends on the value of a,

void regular(int R[], int n) {
int i = 0;
for(int a = 1; i < n; a++) {
int b = a;
while(b != 1) {
if (b % 2 == 0)
b = b / 2;
if (b % 3 == 0)
b = b / 3;
if (b % 5 == 0)
b = b / 5;
else break;
}
if (b == 1) {
R[i] == a;
i = i + 1;
}
}
}更多精彩文章及讨论，请光临枫下论坛 rolia.net

题目的意思是要找到前n个regular number, 要求时间的复杂度是O(n) -bobo123(以马内利); 2009-3-19 (#5127578@0)

现在的年轻人啊，只会花里胡哨的东西。连这么简单的程序都不会写了。 -wangqingshui(忘情水); 2009-3-19 {10689} (#5127591@0)

void regular(int R[], int n)

{

if (n > 0)

{

int index_2 = 0;

int index_3 = 0;

int index_5 = 0;

int regular_2 = 2;

int regular_3 = 3;

int regular_5 = 5;

R[0] = 1;

for (int next_index = 1; next_index < n; ++next_index)

{

int next_regular = min(regular_2, regular_3, regular_5); // O(0)

R[next_index] = next_regular;

if (regular_2 == next_regular)

{

regular_2 = R[++index_2] * 2;

}

if (regular_3 == next_regular)

{

regular_3 = R[++index_3] * 3;

}

if (regular_5 == next_regular)

{

regular_5 = R[++index_5] * 5;

}

// if you like, you can replace index with pointer for better performance.

哇塞。。。。光看明白就好难了。。。高人阿，谢谢谢谢 -ealton(ealton); 2009-3-19 (#5127637@0)

I would recommend you to read some books about algorithms -wangqingshui(忘情水); 2009-3-19 (#5127827@0)

嗯。。。我会的谢谢。。。 -ealton(ealton); 2009-3-20 (#5128553@0)

好算法. 向你学习! -baffin(~噗嗤~); 2009-3-19 (#5128346@0)
搞得也太简单了吧，人家出的题可还有点弯。照你的程序，6 就弄丢了。 -huyou(忽悠); 2009-3-24 (#5140549@0)

你怎么走程序的啊？好程序就是要简洁。这里是n=1000的输出结果。你运行一下看看吧。 -wangqingshui(忘情水); 2009-3-27 {7114} (#5149129@0)
本文发表在 rolia.net 枫下论坛1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36 40 45 48 50 54 60 64 72 75 80 81 90 96 100 108 120 125 128 135 144 150 160 162 180 192 200 216 225 240 243 250 256 270 288 300 320 324 360 375 384 400 405 432 450 480 486 500 512 540 576 600 625 640 648 675 720 729 750 768 800 810 864 900 960 972 1000 1024 1080 1125 1152 1200 1215 1250 1280 1296 1350 1440 1458 1500 1536 1600 1620 1728 1800 1875 1920 1944 2000 2025 2048 2160 2187 2250 2304 2400 2430 2500 2560 2592 2700 2880 2916 3000 3072 3125 3200 3240 3375 3456 3600 3645 3750 3840 3888 4000 4050 4096 4320 4374 4500 4608 4800 4860 5000 5120 5184 5400 5625 5760 5832 6000 6075 6144 6250 6400 6480 6561 6750 6912 7200 7290 7500 7680 7776 8000 8100 8192 8640 8748 9000 9216 9375 9600 9720 10000 10125 10240 10368 10800 10935 11250 11520 11664 12000 12150 12288 12500 12800 12960 13122 13500 13824 14400 14580 15000 15360 15552 15625 16000 16200 16384 16875 17280 17496 18000 18225 18432 18750 19200 19440 19683 20000 20250 20480 20736 21600 21870 22500 23040 23328 24000 24300 24576 25000 25600 25920 26244 27000 27648 28125 28800 29160 30000 30375 30720 31104 31250 32000 32400 32768 32805 33750 34560 34992 36000 36450 36864 37500 38400 38880 39366 40000 40500 40960 41472 43200 43740 45000 46080 46656 46875 48000 48600 49152 50000 50625 51200 51840 52488 54000 54675 55296 56250 57600 58320 59049 60000 60750 61440 62208 62500 64000 64800 65536 65610 67500 69120 69984 72000 72900 73728 75000 76800 77760 78125 78732 80000 81000 81920 82944 84375 86400 87480 90000 91125 92160 93312 93750 96000 97200 98304 98415 100000 101250 102400 103680 104976 108000 109350 110592 112500 115200 116640 118098 120000 121500 122880 124416 125000 128000 129600 131072 131220 135000 138240 139968 140625 144000 145800 147456 150000 151875 153600 155520 156250 157464 160000 162000 163840 164025 165888 168750 172800 174960 177147 180000 182250 184320 186624 187500 192000 194400 196608 196830 200000 202500 204800 207360 209952 216000 218700 221184 225000 230400 233280 234375 236196 240000 243000 245760 248832 250000 253125 256000 259200 262144 262440 270000 273375 276480 279936 281250 288000 291600 294912 295245 300000 303750 307200 311040 312500 314928 320000 324000 327680 328050 331776 337500 345600 349920 354294 360000 364500 368640 373248 375000 384000 388800 390625 393216 393660 400000 405000 409600 414720 419904 421875 432000 437400 442368 450000 455625 460800 466560 468750 472392 480000 486000 491520 492075 497664 500000 506250 512000 518400 524288 524880 531441 540000 546750 552960 559872 562500 576000 583200 589824 590490 600000 607500 614400 622080 625000 629856 640000 648000 655360 656100 663552 675000 691200 699840 703125 708588 720000 729000 737280 746496 750000 759375 768000 777600 781250 786432 787320 800000 810000 819200 820125 829440 839808 843750 864000 874800 884736 885735 900000 911250 921600 933120 937500 944784 960000 972000 983040 984150 995328 1000000 1012500 1024000 1036800 1048576 1049760 1062882 1080000 1093500 1105920 1119744 1125000 1152000 1166400 1171875 1179648 1180980 1200000 1215000 1228800 1244160 1250000 1259712 1265625 1280000 1296000 1310720 1312200 1327104 1350000 1366875 1382400 1399680 1406250 1417176 1440000 1458000 1474560 1476225 1492992 1500000 1518750 1536000 1555200 1562500 1572864 1574640 1594323 1600000 1620000 1638400 1640250 1658880 1679616 1687500 1728000 1749600 1769472 1771470 1800000 1822500 1843200 1866240 1875000 1889568 1920000 1944000 1953125 1966080 1968300 1990656 2000000 2025000 2048000 2073600 2097152 2099520 2109375 2125764 2160000 2187000 2211840 2239488 2250000 2278125 2304000 2332800 2343750 2359296 2361960 2400000 2430000 2457600 2460375 2488320 2500000 2519424 2531250 2560000 2592000 2621440 2624400 2654208 2657205 2700000 2733750 2764800 2799360 2812500 2834352 2880000 2916000 2949120 2952450 2985984 3000000 3037500 3072000 3110400 3125000 3145728 3149280 3188646 3200000 3240000 3276800 3280500 3317760 3359232 3375000 3456000 3499200 3515625 3538944 3542940 3600000 3645000 3686400 3732480 3750000 3779136 3796875 3840000 3888000 3906250 3932160 3936600 3981312 4000000 4050000 4096000 4100625 4147200 4194304 4199040 4218750 4251528 4320000 4374000 4423680 4428675 4478976 4500000 4556250 4608000 4665600 4687500 4718592 4723920 4782969 4800000 4860000 4915200 4920750 4976640 5000000 5038848 5062500 5120000 5184000 5242880 5248800 5308416 5314410 5400000 5467500 5529600 5598720 5625000 5668704 5760000 5832000 5859375 5898240 5904900 5971968 6000000 6075000 6144000 6220800 6250000 6291456 6298560 6328125 6377292 6400000 6480000 6553600 6561000 6635520 6718464 6750000 6834375 6912000 6998400 7031250 7077888 7085880 7200000 7290000 7372800 7381125 7464960 7500000 7558272 7593750 7680000 7776000 7812500 7864320 7873200 7962624 7971615 8000000 8100000 8192000 8201250 8294400 8388608 8398080 8437500 8503056 8640000 8748000 8847360 8857350 8957952 9000000 9112500 9216000 9331200 9375000 9437184 9447840 9565938 9600000 9720000 9765625 9830400 9841500 9953280 10000000 10077696 10125000 10240000 10368000 10485760 10497600 10546875 10616832 10628820 10800000 10935000 11059200 11197440 11250000 11337408 11390625 11520000 11664000 11718750 11796480 11809800 11943936 12000000 12150000 12288000 12301875 12441600 12500000 12582912 12597120 12656250 12754584 12800000 12960000 13107200 13122000 13271040 13286025 13436928 13500000 13668750 13824000 13996800 14062500 14155776 14171760 14348907 14400000 14580000 14745600 14762250 14929920 15000000 15116544 15187500 15360000 15552000 15625000 15728640 15746400 15925248 15943230 16000000 16200000 16384000 16402500 16588800 16777216 16796160 16875000 17006112 17280000 17496000 17578125 17694720 17714700 17915904 18000000 18225000 18432000 18662400 18750000 18874368 18895680 18984375 19131876 19200000 19440000 19531250 19660800 19683000 19906560 20000000 20155392 20250000 20480000 20503125 20736000 20971520 20995200 21093750 21233664 21257640 21600000 21870000 22118400 22143375 22394880 22500000 22674816 22781250 23040000 23328000 23437500 23592960 23619600 23887872 23914845 24000000 24300000 24576000 24603750 24883200 25000000 25165824 25194240 25312500 25509168 25600000 25920000 26214400 26244000 26542080 26572050 26873856 27000000 27337500 27648000 27993600 28125000 28311552 28343520 28697814 28800000 29160000 29296875 29491200 29524500 29859840 30000000 30233088 30375000 30720000 31104000 31250000 31457280 31492800 31640625 31850496 31886460 32000000 32400000 32768000 32805000 33177600 33554432 33592320 33750000 34012224 34171875 34560000 34992000 35156250 35389440 35429400 35831808 36000000 36450000 36864000 36905625 37324800 37500000 37748736 37791360 37968750 38263752 38400000 38880000 39062500 39321600 39366000 39813120 39858075 40000000 40310784 40500000 40960000 41006250 41472000 41943040 41990400 42187500 42467328 42515280 43046721 43200000 43740000 44236800 44286750 44789760 45000000 45349632 45562500 46080000 46656000 46875000 47185920 47239200 47775744 47829690 48000000 48600000 48828125 49152000 49207500 49766400 50000000 50331648 50388480 50625000 51018336 51200000更多精彩文章及讨论，请光临枫下论坛 rolia.net

不错，你的程序是对的，是我误读了。 -huyou(忽悠); 2009-3-29 (#5152107@0)

好象不对 -xniang(123); 2009-3-25 {1998} (#5141200@0)
本文发表在 rolia.net 枫下论坛中间改改
x[(a=0)] = y[(b=B=0)] = z[(c=C=0)] = 1;

while (C<n)
{
int X = x[a] * 2;
int Y = y[b] * 3;
int Z = z[c] * 5;

if ((X < Y) && (X < Z))
x[++a] = y[++B] = z[++C] = X;
else if (Y < Z)
y[++b,++B] = z[++C] = Y;
else
z[++c,++C] = Z;
}
输出:
1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36 40 45 48 50 54 60 64 72 75 8
0 81 90 96 100 108 120 125 128 135 144 150 160 162 180 192 200 216 225 240 243 2
50 256 270 288 300 320 324 360 375 384 400 405 432 450 480 486 500 512 540 576 6
00 625 640 648 675 720 729 750 768 800 810 864 900 960 972 1000 1024 1080 1125 1
152 1200 1215 1250 1280 1296 1350 1440 1458 1500 1536 1600 1620 1728 1800 1875 1
920 1944 2000 2025 2048 2160 2187 2250 2304 2400 2430 2500 2560 2592 2700 2880 2
916 3000 3072 3125 3200 3240 3375 3456 3600 3645 3750 3840 3888 4000 4050 4096 4
320 4374 4500 4608 4800 4860 5000 5120 5184 5400 5625 5760 5832 6000 6075 6144 6
250 6400 6480 6561 6750 6912 7200 7290 7500 7680 7776 8000 8100 8192 8640 8748 9
000 9216 9375 9600 9720 10000 10125 10240 10368 10800 10935 11250 11520 11664 12
000 12150 12288 12500 12800 12960 13122 13500 13824 14400 14580 15000 15360 1555
2 15625 16000 16200 16384 16875 17280 17496 18000 18225 18432 18750 19200 19440
19683 20000 20250 20480 20736 21600 21870 22500 23040 23328 24000 24300 24576 25
000 25600 25920 26244 27000 27648 28125 28800 29160 30000 30375 30720 31104 3125
0 32000 32400 32768 32805 33750 34560 34992 36000 36450 36864 37500 38400 38880
39366 40000 40500 40960 41472 43200 43740 45000 46080 46656 46875 48000 48600 49
152 50000 50625 51200 51840 52488 54000 54675 55296 56250 57600 58320 59049 6000
0 60750 61440 62208 62500 64000 64800 65536 65610 67500 69120 69984 72000 72900
73728 75000 76800 77760 78125 78732 80000 81000 81920 82944 84375更多精彩文章及讨论，请光临枫下论坛 rolia.net

不好意思，我C语法已经忘得差不多了。有点不习惯你的程序的可读性。我的程序的时间开销：n-1个乘法，2(n-1)个加法，5(n-1)+2个比较，6(n-1)+7个赋值。空间开销为：n+8个整数 -wangqingshui(忘情水); 2009-3-27 {233} (#5149141@0)
int min(int a, int b, int c)
{
if (a > b)
{
a = b;
}

if (a > c)
{
a = c;
}

return a;
}

@Florida

你怎么走程序的啊？好程序就是要简洁。这里是n=1000的输出结果。你运行一下看看吧。

Replies, comments and Discussions:

More Topics